diff --git a/CMakeLists.txt b/CMakeLists.txt
index 2aa5d92a7..ad18b67e7 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -1076,7 +1076,7 @@ if (NOT ANDROID OR TERMUX)
     install(DIRECTORY papers DESTINATION ${CMAKE_INSTALL_DOCDIR}/other)
     install(FILES LICENSE DESTINATION ${CMAKE_INSTALL_DATADIR}/licenses/furnace)
     if (WITH_DEMOS OR WITH_INSTRUMENTS OR WITH_WAVETABLES)
-      set(FURNACE_DATADIR ${CMAKE_INSTALL_DATADIR}/furnace)
+      set(FURNACE_DATADIR ${CMAKE_INSTALL_FULL_DATADIR}/furnace)
       if (WITH_DEMOS)
         install(DIRECTORY demos DESTINATION ${FURNACE_DATADIR})
       endif()
@@ -1086,7 +1086,7 @@ if (NOT ANDROID OR TERMUX)
       if (WITH_WAVETABLES)
         install(DIRECTORY wavetables DESTINATION ${FURNACE_DATADIR})
       endif()
-      add_compile_definitions(FURNACE_DATADIR="${CMAKE_INSTALL_PREFIX}/${FURNACE_DATADIR}")
+      add_compile_definitions(FURNACE_DATADIR="${FURNACE_DATADIR}")
       if (SHOW_OPEN_ASSETS_MENU_ENTRY)
         add_compile_definitions(SHOW_OPEN_ASSETS_MENU_ENTRY)
       endif()